Slow make and break switch



Dec. 7, 1943. R. H. BENTLEY SLOW MAKE AND BREAK SWITCH Filed July 23,1942 J. .1 1 E q ,1 T 14 a5 zz 76 Even??? ROBERT H. BENTLEY M MMPatented Dee. 7, 1943 SLOW MAKE AND BREAK SWITCH Robert 11. Bentley,Hartford, Conn., assignor to The Arrow-Hart & Hegeman Electric Company,Hartford, Conn., a corporation of Connecticut Application July 23, 1942,Serial No. 452,035

6 Claims. (Cl. 200-16) This invention relates to improvements inelectric switches, and more particularly to improvements in slow makeand break switches for alternating current circuits.

It is an object of this invention to provide a switch of the above typein small size but of relatively large current controlling capacity.

Another object of the invention is to provide an improved form ofmulti-pole switch of the above type provided with means to ensure thejoint opening of the circuit in all poles as the switch is operated.

Another object of the invention is to simplify and improve the form ofmulti-pole switches of the above type.

Other objects and advantages of the invention will become apparent as itis described in connection with the accompanying drawing.

In the drawing Fig. 1 is a longitudinal elevational mid-section view ofa switch embodying the invention.

Fig. 2 is a plan view of the switch with the cover and parts carriedthereby removed.

Fig. 3 is a'transverse section view of the switch of Fig. 1 with thesection taken along line 3-3.

Fig. 4 is a transverse section view of the switch illustrated in Fig. 1,with the section being taken along line 4-4 of Fig. 2.

Fig. 5 is a perspective view of the contact operating yoke or bracketmember.

Fig. 6 is a perspective view of one of the insulating plungers used forthe outside poles of the switch invention shown in the preceding Figs.1-4.

Fig. 7 is a perspective view of the insulating plunger member used onthe middle pole of the switch invention shown in the preceding Figs.1-4.

Referring to the drawing, the switch mechanism is mounted in arectangular base Ill of molded insulating material and is covered by arectangular cover II, also of molded insulating material and providedwith a central elevation or rib ll running longitudinally. The elevatedportion of the cover it is hollowed out from the top for the receptionof actuating mechanism comprising a stamped sheet metal lever I whichpivots about an axle pin it passing through a hearing aperture in thecentral portion of the operating lever and seating in bearing recesses2n hollowed out of the top surface of the elevated portion ll. The axlepin is held in these bearing recesses by an insulating liner plate 24and a switch mounting strap 22, which lie above the top surface of theelevated portion I4 and are secured thereto by bolts ll passing base andcover and taking into threaded apertures in the supporting strap orplate 22.

The inner end of the operating member is is enlarged to provide anarcuate cam surface iGc for engagement with an anti-friction roller 30associated with the contact moving yoke of the switch, as hereinaftermore fully described.

For the purpose of maintaining the operating lever IS in switch on and"o positions, a bowed leaf spring member 21 having an arcuate hump 21ain the center thereof is seated in the bottom of the recess within theelevated portion ll of the cover. This leaf spring is slotted centrallyto provide for passage therethrough of the cam portion of the operatingmember ii. The operating member is provided with anti-friction rollers28 mounted upon an axle pin 29 extending through the inner end of theoperating member I 8 in such position as to cause the anti-frictionroller to be engaged with the arcuate hump 21a of the leaf spring, asillustrated in Fig. 1, when the operating member is in switch on andswitch of! position and to be held in such positions by the force of theleaf spring member.

The current carrying parts are all located in the base i0. Each pole ofthe device has its contacts located in a separate cavity or chamberrunning longitudinally of the base. Fixed contacts are preferablymounted upon ledges at opposite ends of their respective chambers. Thefixed contacts, preferably stamped from sheet metal with contact buttonsmounted on one end thereof facing downwardly, are secured in place byhollow rivets passing through the ends of the base so as to afford wireterminal connection means, which receive terminal screws in the usualmanner. For bridging the pairs of fixed contacts of each pole, aseparate bridging member, such as 40, is provided for each pole.Conventionally the bridging member is provided with contact buttons oneach end to engage with contact buttons of the fixed contacts.Preferably the bridging member will have a hollow boss formed in thecentral portion thereof to afford a seat or guide for a compressionspring 44 which rests upon the floor of the base about a boss 46 formedin the floor, whereby the spring continually urges the movable contactupwardly into circuit closing position.

In the central portion of each of the separate contact chambers there isprovided an offset recess, such as 50 and 52, the walls of which pro;vide guide means for insulating plungers, such as 58 and It. Theplungers 56 for the outside through the I6 poles are identical and haverectangular prismatic form, as shown in Fig. 6, while the plunger forthe inside pole has rectangular prismatic form as shown in Fig. 7. It isdesirable to have the plunger for the inner pole of different form fromthe plungers for the outside poles, by reason of the improved type ofoperating mechanism I have devised. The plungers are operated by a yokeor bracket member 60 stamped from sheet metal and having side arms GIand a bifurcated center arm 62. The ends of these arms are rounded intocam surfaces so as to reduce friction as these arms engage with theplungers in the several contact chambers. Referring particularly to Fig.2, it will be noted that the operating yoke 60 is positioned so as tocause the arms to extend toward the center of the base from thetransverse portion of the frame which is located at one end of the base.To provide for rocking the operating yoke, a pair of lugs 63 aresymmetrically bent down from the plane of the end edge of the transverseportion of the frame and have their ends seated in recesses 64, adjacentthe end wall of the base Ill. The arms 6i engage in slots on the uppersurface "of the plungers 56 and the ends of the bifurcated arm 62 engagein a recess in the top of plunger 58 for the purpose of depressing theplungers as the arms are depressed or pivot downwardly about the pointsof pivotal engagement of the lugs 83 in recesses 64.

In order to move the yoke 60 with minimum resistance as the operatinglever i6 is manipulated, the central arm 62 of the yoke has the endportions of its bifurcations provided with bearing slots 66 receivingthe axle 68 of the anti-friction roller 30, which is engaged by the camsurface 160 of the operating lever.

From the foregoing, it will now be readily understood that as theoperating member I6 is rocked about its pivot IS, the cam surface ificengaging with and'pressing upon the anti-friction roller 30 will causethe operating yoke or bracket Bil to be rocked downwardly about thepivot lugs 63. This downward rocking movement of the bracket causes theplungers 56 and 58 to descend by reason of the engagement of the arms GIand 62 of the yoke with these plungers. Since the flat bottoms of theplungers rest upon the fiat upper surface of the bridging contacts ofthe switch, these contacts are caused to descend with the plungers anddisengage from the fixed contacts, whereby the switch is moved toopencircuit position. The provision of the yoke 69 in the device ensuresthe opening of the contacts in all of the poles simultaneously. This isan improvement upon certain prior devices, wherein the contacts of onepole would open While those of another would often remain engaged due tothe faulty operation or defective design of the contact openingmechanism.

Variations within the scope of my invention may occur to those skilledin the art.

I claim:

1. In an electric switch, an insulating base having a, plurality ofcavities, a set of cooperating fixed and movable contacts in eachcavity, a separate insulating plunger engaging each movable contact, ayoke member pivotally mounted about a fixed pivot and having portionsengaging said plungers to simultaneously move said contacts, and meansto move said yoke to cause said contacts to separate.

2. In an electric switch, an insulating base having therein a pluralityof longitudinal unbroken walls forming a plurality of separate cavitiesextending lengthwise of said base, a separate set of cooperating fixedand movable contacts in each cavity, spring means normally urging saidcontacts into engagement, an individual insulating plunger in eachcavity and guided in movement by the walls of the cavity for moving themovable contact, a rigid yoke member having a pivotal bearing at one endof said base and having portions extending lengthwise of the base intoengagement with said plungers for moving them jointly, a cover for saidbase, and manual operating means extending through said cover intooperating engagement with said yoke member.

3. In an electric switch, an insulating base having therein a pluralityof longitudinal unbroken walls forming a plurality of separate cavitiesextending lengthwise of said base, a separate set of cooperating fixedand movable contacts in each cavity, spring means normally urging saidcontacts into engagement, an individual insulating plunger in eachcavity and guided in movement by the walls of the cavity for moving themovable contact, a rigid yoke member having a pivotal hearing at one endof said base and having portions extending lengthwise of the base intoengagement with said plungers for moving them jointly, anti-frictionmeans on said yoke member, a cover for said base, and operating meansextending through said cover and engaging said anti-friction means formoving said yoke with minimum friction.

4. In an electric switch, an insulating base .having a plurality ofcavities, a set of cooperating fixed and movable contacts in eachcavity, a "separate insulating plunger engaging each movable contact, ayoke member pivotally mounted about a fixed pivot and having portionsengaging said plungers to simultaneously move said contacts, a. cover,operating means extending through the cover to move said yoke and causesaid contacts to separate, and anti-friction means between saidoperating means and yoke to reduce friction.

5. In an electric switch, an insulating base having a plurality ofcavities, a set of cooperating fixed and movable contacts in eachcavity, a separate insulatingplunger engaging with each movable contactand guided by the base for rectilinear movement, a yoke member pivotallyengaging in bearing means near one end of said base and having armsengaging said plungers, and operating means for moving said yoke memberto pivot it and move said plungers and contacts.

6. In an electric switch, an insulating base having a plurality ofcavities, a set of cooperating fixed and movable contacts in eachcavity, a separate insulating plunger engaging with each movable contactand guided in movement by the base, a yoke member pivotally engagingbearing means near one end of said base and having arms engaging saidplungers, one of said arms having an anti-friction roller mountedthereon, and an operating lever having a cam surface engaging saidroller for pivoting said yoke member to move said plungers and contacts.

ROBERT H. BENTLEY.

